1. Field of the Invention
The present invention pertains generally to vent exhaust pipes and, in particular, to roof jacks for vent exhaust pipes.
2. Description of Related Art
Roofs and other coverings over commercial, residential and recreational structures (hereinafter collectively referred to as “structure”) often have openings configured to allow the penetration of vents, piping and other conduits (hereinafter collectively referred to as “conduit”) into and out of the structure. For example, the roof of a structure may include conduits for ventilation piping or ducts, electrical, cable or any other reason that an opening in a structure may be required.
One technique used to cover a conduit is a traditional roof jack, as depicted in FIG. 1. When a conduit is passed through the roof to the exterior of the home to provide ventilation, a “roof jack” is typically installed over the pipe to prevent water from entering the structure. The roof jack covers the “mouth” of the pipe to prevent water from entering the pipe itself as well as to prevent water from entering the hole that is cut into the roof. There is a square flange (10), a cylinder (12) and a vent cap (14). While such prior art systems provide ventilation, a problem arises because different structures often have a different roof “pitch” a different degree of slope. Roofs generally range from zero degrees of angle to 45 degrees. In order to keep a roof jack's cylinder vertical while the flange/flashing is flush with the roof surface, multiple variations are constructed and manufactured for the particular slope or pitch of the roof on which the roof jack is to be used. This requires roof jack suppliers to maintain a relatively large inventory of roof jacks in order to accommodate the full range of slopes or pitch which are encountered in the building industry. There is also the issue of requiring multiple stock keeping units (SKU's). Roof jack suppliers are faced with the problem of high costs and high storage space if they want to be able to supply roof jacks accommodating the full range of slopes. This is also costly for those constructing the structure. For example, They may find out that during the installation the wrong pitch roof jack was ordered. This can cause costly delays and uncovered openings in the roof of the structure.